KΛ(1405)K\Lambda(1405) configuration of the KKˉNK\bar{K}N system

We study the $K\Lambda(1405)$ configuration of the $K\bar{K}N$ system by considering $K\pi\Sigma$ as a coupled channel. We solve the Faddeev equations for these systems and find confirmation of the existence of a new $N^{*}$ resonance around 1920 MeV with $J^{\pi}=1/2^{+}$ predicted in a single-channel potential model and also found in a Faddeev calculation as an $a_{0}(980)N$ state, with the $a_{0}(980)$ generated in the $K\bar{K}$, $\pi\eta$ interaction.Comment: Published versio

On the Critical Behaviour of Heat Conducting Sphere out of Hydrostatic Equilibrium

We comment further on the behaviour of a heat conducting fluid when a characteristic parameter of the system approaches a critical value.Comment: 4 pages, emTex (LaTex 2.09), submitted to Classical and Quantum Gravity (Comments and Addenda

Neutrino Nucleosynthesis of radioactive nuclei in supernovae

We study the neutrino-induced production of nuclides in explosive supernova nucleosynthesis for progenitor stars with solar metallicity and initial main sequence masses between 15 M$_\odot$ and 40 M$_\odot$. We improve previous investigations i) by using a global set of partial differential cross sections for neutrino-induced charged- and neutral-current reactions on nuclei with charge numbers $Z < 76$ and ii) by considering modern supernova neutrino spectra which have substantially lower average energies compared to those previously adopted in neutrino nucleosynthesis studies. We confirm the production of $^7$Li, $^{11}$B, $^{138}$La, and $^{180}$Ta by neutrino nucleosynthesis, albeit at slightly smaller abundances due to the changed neutrino spectra. We find that for stars with a mass smaller than 20 M$_\odot$, $^{19}$F is produced mainly by explosive nucleosynthesis while for higher mass stars it is produced by the $\nu$ process. We also find that neutrino-induced reactions, either directly or indirectly by providing an enhanced abundance of light particles, noticeably contribute to the production of the radioactive nuclides $^{22}$Na and $^{26}$Al. Both nuclei are prime candidates for gamma-ray astronomy. Other prime targets, $^{44}$Ti and $^{60}$Fe, however, are insignificantly produced by neutrino-induced reactions. We also find a large increase in the production of the long-lived nuclei $^{92}$Nb and $^{98}$Tc due to charged-current neutrino capture.Comment: 6 pages, 2 figures, 2 table

Gestión de clientes de servicios deportivos: un modelo de dinámica de sistemas

[ESP] Esta investigación propone un modelo general de gestión de clientes de servicios deportivos que pretende mejorar la dirección estratégica de los mismos. Para ello, se han integrado variables de la oferta y la demanda, en un planteamiento principalmente enfocado en la perspectiva de marketing. La dinámica de sistemas ha sido la metodología utilizada, con el fin de manejar la complejidad inherente al estudio de este tipo de fenómenos. Además, el modelo se presenta con un enfoque didáctico, en aras de facilitar su comprensión, describiendo las ecuaciones, aportando la sintaxis de programación, y dejando las puertas abiertas a la mejora y posible reformulación del mismo. [ENG] In this research a customer management model of sports services is formulated. This model may serve as a strategic tool that will allow managers to better understand the flow of customers in the sports centre. System dynamics has been used in order to deal with this complex task. The model is explained using a didactic approach. Finally, the equations and the program syntax are provided